Midsole lattice with hollow tubes for footwear

Abstract

An article of footwear includes an upper and a midsole connected to upper. The midsole includes a lattice structure with a plurality of laths. The lattice structure includes at least one hollow lath such that an inner void is formed within the at least one hollow lath. A loose granular material is provided within the inner void of the at least one hollow lath.

What is claimed is: 
     
       1. An article of footwear comprising:
 an upper; and 
 a sole member connected to the upper, the sole member including a plurality of tubular structures, the plurality of tubular structures at least partially filled with a loose granular material, wherein the plurality of tubular structures are provided as a plurality of laths that form a lattice structure. 
 
     
     
       2. The article of footwear of  claim 1  wherein the loose granular material is a powder. 
     
     
       3. The article of footwear of  claim 2  wherein the powder is provided by a non-fused powder comprised of a first material, and the lattice structure is provided by a fused powder comprised of the first material. 
     
     
       4. The article of footwear of  claim 1 , the plurality of laths positioned in at least a first zone and a second zone of the sole member, each lath in the first zone having a first girth that is substantially different from a second girth of each lath in the second zone. 
     
     
       5. The article of footwear of  claim 1 , wherein the plurality of laths are varied in diameter throughout the sole member. 
     
     
       6. The article of footwear of  claim 1 , wherein a plurality of distinct pockets are formed in the plurality of laths. 
     
     
       7. The article of footwear of  claim 1 , wherein a recess is formed in the lattice structure and a resilient insert is positioned within the recess. 
     
     
       8. The article of footwear of  claim 1  wherein the loose granular material comprises a nylon material. 
     
     
       9. The article of footwear of  claim 1  wherein the granular material is between 10 microns and 100 microns in diameter. 
     
     
       10. The article of footwear of  claim 1  wherein the tubular structures are substantially cylindrical in shape and between 1 mm and 6 mm in diameter. 
     
     
       11. The article of footwear of  claim 1  wherein the tubular structures are substantially hollow but for the loose granular material. 
     
     
       12. The article of footwear of  claim 11  wherein the loose granular material is packed granular material that fills between about 25% and 75% of space within the tubular structures. 
     
     
       13. The article of footwear of  claim 1  wherein the loose granular material is comprised of a non-fused powder and the tubular structures are comprised of a fused powder. 
     
     
       14. The article of footwear of  claim 1 , the sole including an outsole, an insole, and a midsole, the tubular structures provided on the midsole. 
     
     
       15. An article of footwear comprising:
 an upper; 
 a midsole connected to upper, the midsole including a lattice structure including a plurality of laths, the lattice structure including at least one hollow lath such that an inner void is formed within the at least one hollow lath; and 
 a loose granular material provided within the inner void of the at least one hollow lath. 
 
     
     
       16. The article of footwear of  claim 15  wherein each of the plurality of laths is a tubular structure and the at least one hollow lath defines an inner channel extending through the tubular structure, wherein the loose granular material within the inner channel is comprised of a non-fused powder and the tubular structure is comprised of a fused powder. 
     
     
       17. The article of footwear of  claim 15  wherein the lattice structure includes a plurality of hollow laths with a plurality of pockets formed within the hollow laths, wherein the loose granular material is positioned in each of the plurality of pockets. 
     
     
       18. The article of footwear of  claim 15  further comprising an outsole connected to the midsole such that lattice structure of the midsole is positioned between the upper and the outsole. 
     
     
       19. A method of making an article of footwear comprising:
 ejecting a granular material onto each of a plurality of layers of a lattice structure of a sole member; 
 sintering a first portion of the ejected granular material in each of the plurality of layers to form a plurality of tubular structures in the sole member, the plurality of tubular structures forming a plurality of laths for the lattice structure; 
 leaving a second portion of the ejected granular material un-sintered in each of the plurality of layers such that loose granular material is provided within and at least partially fills the plurality of tubular structures; and 
 coupling the sole member including the lattice structure to an upper of the article of footwear.